Problem: Simplify the following expression: $t = \dfrac{z}{7z + 6} + \dfrac{-z - 7}{7z + 6}$
Answer: Since the expressions have the same denominator we simply combine the numerators: $t = \dfrac{z - z - 7}{7z + 6}$ Combine like terms: $t = \dfrac{-7}{7z + 6}$